The invention relates to a light application unit for combined photodynamic diagnosis (PDD) and/or photodynamic therapy (PDT) of diseases of the parodontium and the teeth.
The invention further relates to the use of 5-amino levulinic acid or a derivative thereof for producing a pharmaceutical preparation for photodynamic diagnosis and/or photodynamic therapy of diseases of the parodontium and the teeth.
The invention still further relates to an apparatus for applying the pharmaceutical preparation to the parodontium.
The use of 5-amino levulinic acid for photodynamic diagnosis (PDD) for the detection of bladder carcinoma is known from the article “Endo World” URO No. 17/1-D, 1997 of Karl Storz GmbH & Co., Tuttlingen, Germany and Karl Storz Endoscopy, USA. As is disclosed there, certain photo-sensitizers together with a special light can be used to detect malignant or other types of tissue (photodynamic diagnosis, PDD) and to destroy such tissue (photodynamic therapy, PDT). The phenomenon is observed in malignant tissue, healthy tissue does not show this phenomenon.
This phenomenon is based on the properties of 5-amino levulinic acid and consequently the induced formation of photo-sensitive protoporphyrine IX (PPIX). 5-amino levulinic acid is a precursor of the photo-sensitizer protoporphyrine IX, so that the amount of protoporphyrine IX is increased by administration of this precursor. The precursor does not become enriched and transform into PPIX in healthy tissue.
The precursor to the photo-sensitizer is applied by installation, flushing, inhalation, orally or topically. This tissue can be excited to become fluorescent with a corresponding light application system and this fluorescence is observed, which makes possible the photodynamic diagnosis (PDD). Furthermore it has been found that a photo-toxic effect occurs induced by PPIX, which opens up the possibility of photodynamic therapy (PDT).
The German patent applications DE 197 21 454 and DE 196 39 653 disclose apparatus for photodynamic diagnosis using fluorescence induced by 5-amino levulinic acid in biological tissue in vivo.
The object of the present invention is to expand the utilization of 5-amino levulinic acid and optionally derivatives thereof and to provide the corresponding apparatus.